Mouth guard



FIG. 1 is a top, rear, side perspective view of a mouth guard, showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a side elevation view thereof;

FIG. 6 is an opposite side elevation view thereof; and,

FIG. 7 is a bottom plan view thereof. 

CLAIM The ornamental design for a mouth guard, as shown and described. 